A team of researchers at the University of Sheffield and Boston’s Children Hospital, Harvard Medical School have created a robot that can be implanted into the body to aid the treatment of oesophageal atresia, a rare birth defect that affects a baby's oesophagus.
Previously, sufferers of oesophageal atresia were treated by a procedure known as the Foker technique, whereby sutures were inserted into the oesophagus to gradually add tension to the atresia over time. The new method builds on this idea, but instead of using sutures to add tension, it uses a small robot.
The diminutive robot is implanted into the infant and is attached to the oesophagus by two rings. A small motor in the robot gradually adds tension and stimulates the cells. The robot adjusts its own tension by a feedback system, which receives information from two embedded sensors. The first sensor is a tension sensor and the second is a displacement sensor. Together, these measure the properties of the tissue and allow the robot to make adjustments when needed.
“Doctors have been performing the Foker procedure as they realised that tissue lengthening can be achieved by pulling on the tissue”, said Dr Dana Damian from the Department of Automatic Control and Systems Engineering at the University of Sheffield “However, it is unknown how much force should be applied to produce tissue lengthening. Although the technique is one of the best standards, sometimes the sutures surgeons attach to the oesophagus can tear which can result in repetitive surgeries or scar tissue can form that can cause problems for the patient in the future.
Oesophageal atresia is a rare condition in which the baby is born with a gap in between the upper and lower parts of the oesophaegus, meaning that food cannot reach the stomach. This condition affects 1 in 4000 infants in the United States.
“The robot we developed addresses this issue because it measures the force being applied and can be adapted at anytime throughout the treatment,” continued Damian. “With it being implanted in the patient, it means they have - in effect - a doctor by their side all the time, monitoring them and changing their treatment when needed.”
“This is the first step in adaptive regenerative-based treatments of tissues. We have made a device that can provide long-term control of the tissue growth using on-board medical expertise. We further want to look at other tubular tissues, such as the intestine and the vascular system, to see if this sort of technology can be used to help with other conditions, such as Short Bowel Syndrome.”
The method has so far been tested in pigs, and has shown that the applied forces can induce cell proliferation and lengthening of the organ without a reduction in diameter, while the animal is awake. Testing in swine is a useful analogy, as both pigs and babies are what is referred to as “technologically hostile” environments- due to their uncooperative nature and random movements.